scholarly journals Studies on The Metabolism of Model Compounds Related to Soil Humic Acid I. The Decomposition of N-(O-Carboxyphenyl)Glycine

1964 ◽  
Vol 17 (1) ◽  
pp. 153 ◽  
Author(s):  
JN Ladd
Keyword(s):  
Amino Acid ◽  
Humic Acid ◽  
Nitrogen Atom ◽  
Aromatic Ring ◽  
Model Compound ◽  
Model Compounds ◽  
Adaptation Studies ◽  
Soil Humic Acid ◽  
Achromobacter Sp

An Achromobacter sp. which has been isolated from Urrbrae loam adaptively oxidizes N -(o-carboxyphenyl)glycine, selected as a model compound since it con� tains an aromatic ring bonded directly to the nitrogen atom of an a-amino acid, as proposed for humic acid polymers. Simultaneous adaptation studies indicate that this compound is metabolized via anthranilate, 5-hydl'Oxyanthranilate, and 2,5- dihydroxybenzoate. The rate of oxidation of N -(o-carhoxyphenyl)glycine is inhibited by N.methyianthranilate and salicylate, the latter by inhibiting the conversion of anthranilate to 5-hydroxyanthranilate.

Carbon13 NMR of Z- and E-Doxepin Hydrochloride

1986 ◽  
Vol 40 (4) ◽  
pp. 538-542 ◽  
Author(s):  
Dorothy K. Wyatt ◽  
Nina M. Roscher ◽  
Lee T. Grady
Keyword(s):  
Chemical Shift ◽  
Aromatic Ring ◽  
Model Compound ◽  
Antidepressant Drug ◽  
Clinical Importance ◽  
2D Nmr ◽  
Chemical Shift Assignments ◽  
Model Compounds ◽  
Nmr Studies ◽  
And Inversion

Carbon13 chemical shift assignments are reported for Z- and E-doxepin hydrochloride [ Z- and E-N,N,-dimethyl-dibenz[b,e]oxepin-delta-11(6H)], gamma-propylamine hydrochloride, and related model compounds. Doxepin hydrochloride, a mixture of approximately 85% E- and 15% Z-isomer is of clinical importance as an antidepressant drug. Previous proton NMR studies indicated that the dibenz(b,e,)oxepin ring exists in two conformations. This study indicates that one conformation may be favored for each isomer with alkylamino olefinic substituent orientation above the most adjacent aromatic ring. Homoand heteronuclear shift-correlated 2D NMR, selective INEPT, selective and off-resonance decoupling, and inversion-recovery ( T1) experiments as well as model compound comparisons were used in assignments.

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

Configuration on the C=N double bond of monosubstituted amidines and amidoximes

1989 ◽  
Vol 54 (12) ◽  
pp. 3245-3252 ◽  
Author(s):  
Bernard Tinant ◽  
Janine Dupont-Fenfau ◽  
Jean-Paul Declercq ◽  
Jaroslav Podlaha ◽  
Otto Exner
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Steric Effects ◽  
Model Compounds ◽  
X Ray ◽  
Analogous Model

Configuration on the C=N double bond of amidines and amidoximes is controlled by steric effects on the second nitrogen atom but there is a difference in the case of N’-monosubstituted derivatives: amidines prefer E configuration (conformation around the C-N bond sp) and amidoximes Z configuration (conformation ap). This was confirmed by the X-ray structures of two analogous model compounds N,N’-dimethyl-4-nitrobenzamidine (monoclinic, P21c, a = 10.855(3), b = 11.043(3), c = 8.593(3) Å, β = 105.69(2)°, V = 991.8(5) Å3, Z = 4, Dx = 1.29 g cm-3, CuKα, λ = 1.5418 Å, μ = 7.91 cm-1, F(000) = 408, T = 291 K, R = 0.065 for 1 265 observed reflections) and N’-methyl-4-nitrobenzamidoxime (monoclinic, P21/a, a = 6.699(2), b = 24.178(9), c = 6.075(2) Å, β = 106.20(3)°, V = 944.9(6) Å3, Z = 4, Dx = 1.37 g cm-3, CuKα, λ = 1.5418 Å, μ =9.22 cm-1, F(000) = 408, T = 291 K, R = 0.079 for 1 278 observed reflections).

Dirhodium-Catalyzed Chemo- and Site-Selective C–H Amidation of N,N-Dialkylanilines

Synlett ◽  
2020 ◽  
Author(s):  
Yoshihiro Ueda ◽  
Gong Chen ◽  
Kenta Arai ◽  
Kazuhiro Morisaki ◽  
Takeo Kawabata
Keyword(s):  
Nitrogen Atom ◽  
Aromatic Ring ◽  
Methyl Group ◽  
Site Selective

AbstractA method for dirhodium-catalyzed C(sp3)–H amidation of N,N-dimethylanilines was developed. Chemoselective C(sp3)–H amidation of N-methyl group proceeded exclusively in the presence of C(sp2)–H bonds of the electron-rich aromatic ring. Site-selective C(sp3)–H amidation proceeded exclusively at the N-methyl group of N-methyl-N-alkylaniline derivatives with secondary, tertiary, and benzylic C(sp3)–H bonds α to a nitrogen atom.

Synthesis and chromatographic characterization of [Tc-99m]technetium-humic acid species

2000 ◽  
Vol 88 (2) ◽  
Author(s):  
D. Rößler ◽  
K. Franke ◽  
R. Süß ◽  
E. Becker ◽  
H. Kupsch
Keyword(s):  
Humic Acid ◽  
Stannous Chloride ◽  
Gel Permeation Chromatography ◽  
Paper Electrophoresis ◽  
Gel Permeation ◽  
Soil Humic Acid ◽  
Chromatographic Characterization ◽  
Ph Dependent ◽  
Layer Chromatography

A natural moor soil humic acid (HA) was labeled with Tc-99m via reduction of pertechnetate with stannous chloride. The humic acid species obtained were characterized by thin layer chromatography (TLC), gel permeation chromatography (GPC), sequential chromatographic analysis (SCA), paper electrophoresis and micropore filtration. Labeling was found to take place in all ranges of molecular weight. Due to the complex humic acid composition and the formation of hydroxo species the labeling yields strongly depend on the separation conditions, ranging from 42% to 80%. The pH-dependent distribution of mobile and immobile species was determined by SCA for HTcO

scholarly journals Molecular characterization of an end-residue of humeomics applied to a soil humic acid

RSC Advances ◽  
2014 ◽  
Vol 4 (45) ◽  
pp. 23658-23665 ◽  
Author(s):  
A. Nebbioso ◽  
A. Piccolo ◽  
M. Lamshöft ◽  
M. Spiteller
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Molecular Characterization ◽  
Natural Organic Matter ◽  
Molecular Composition ◽  
Chemical Fractionation ◽  
Soil Humic Acid

Humeomics encompasses step-wise chemical fractionation and instrumental determination to fully characterize the heterogeneous molecular composition of natural organic matter.

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